Chapter 6: Work and Energy

2. A machine that works without energy loss is called:

3. Energy losses mainly occur due to:

4. George is studying energy conversion. He drops a ball from a height of 5 meters. As the ball falls, its potential energy is converted to kinetic energy. What is the kinetic energy of the ball just before it hits the ground? (Assume mass = 1 kg, g = 10 m/s²)

5. If force is applied but no displacement occurs, the work done is:

6. Fatima is calculating the potential energy of a 2 kg object placed at a height of 3 meters above the ground. What is the potential energy? (Take g = 10 m/s²)

7. Patricia is studying the kinetic energy formula. She knows that kinetic energy is given by KE = ½ mv². If the mass of an object is doubled, what happens to its kinetic energy if the speed remains constant?

8. Xia is studying the law of conservation of energy. She knows that energy can be converted from one form to another. In a hydroelectric dam, what energy conversion takes place?

9. Lara is studying power. She knows that power is the rate of doing work. A motor does 500 J of work in 10 seconds. What is the power of the motor?

10. Emma is studying the kinetic energy of a moving car. The car has a mass of 1000 kg and is moving at a speed of 20 m/s. What is the kinetic energy of the car?

11. Tina is studying energy forms. She knows that energy can exist in different forms. Which of the following is a form of energy?

12. Energy possessed by a moving object is called:

13. Zara is studying kinetic energy. She knows that kinetic energy depends on mass and speed. If the speed of a moving object is doubled, what happens to its kinetic energy?

14. Rachel is studying work. She knows that work is done when a force moves an object in the direction of the force. If the force and displacement are perpendicular to each other, what is the work done?

15. Nora is studying energy resources. She knows that non-renewable resources are finite and will eventually run out. Which of the following is a non-renewable resource?

16. Rachel is studying power. She knows that power is the rate at which work is done. A machine does 1000 J of work in 5 seconds. What is the power of the machine?

17. Waseem is studying power. He knows that power is measured in watts. What is the formula for power?

18. According to conservation of energy, total energy remains:

19. Quinn is studying tides. He knows that tidal energy is generated by the movement of water due to tides. What causes tides?

20. Tina is studying power. She knows that power is the rate of doing work. If a machine does 1000 J of work in 2 seconds, what is its power?

21. The SI unit of power is:

22. Julia is studying nuclear fuels. She knows that nuclear energy is obtained from the nucleus of atoms. Which of the following is a nuclear fuel?

23. Khalid is studying biomass fuels. He knows that biomass is organic matter that can be used as fuel. Which of the following is a biomass fuel?

24. David is studying fossil fuels. He knows that fossil fuels are formed from the remains of ancient organisms. Which of the following is a fossil fuel?

25. Yusuf is studying the conservation of energy. He knows that the total energy in an isolated system remains constant. In a swinging pendulum, where is the kinetic energy maximum?

26. Bilal is studying the work done by a force. He applies a force of 100 N to move an object by 2 meters in the direction of the force. What is the work done?

27. Which of the following is a renewable energy source?

28. Efficiency of a machine is always:

29. Chloe is lifting a 5 kg mass vertically upward to a height of 2 meters. She wants to calculate the work done against gravity. What is the work done? (Take g = 10 m/s²)

30. Which energy source is non-renewable?